This invention relates to centrifuges.
Centrifuge technology has long been used for separating, lighter material from heavier material from initial material consisting of a combination of the two. Centrifuge technology has been implemented in medical, industrial, and public service sectors in various specific applications where separation technology is beneficial.
The effectiveness of presently known centrifuge technology depends on the level of the separating force (centrifugal force) generated by the centrifuge and the residence time of the material under the separating force. Virtually all centrifuges rely on some type of rotary motion to generate the separating force, and thus the level of the separating force generated depends on the size (moment arm) of the centrifuge and the speed at which the centrifuge is rotated. To generate a given level of separating force, a small-scale centrifuge must be driven at a higher revolutions per minute than a large-scale centrifuge.
The residence time of the material under the separating force is dependent upon the flow-path of the material through the centrifuge. The flow-path is defined by the internal structure of the centrifuge, and is sometimes limited by the type of centrifuge. Typically, the higher the residence time of a material under a given separation force, the better the separation of the light material from the heavy material.
Existing centrifuge technology is limited in its ability to allow changes to the separation force and/or the residence time.
In addition, existing relatively large-scale centrifuge technology capable of handling relatively large inflow rates such as 100 G.P.M., is not conducive to portable use in a self-contained unit. The structures are difficult to transport, require frequent skilled maintenance, and often do not allow simple modification of the separation force or residence time to adjust to varying raw material conditions, or final material requirements.
It is with the foregoing issues that the centrifuge of the present invention was developed.
The present invention in general terms concerns a centrifuge having opposing laterally extending arms with concentric tubular baffles therein defining a serpentine flow path. The centrifuge is rotatably mounted in a frame to allow easy transportation, and has an external drive interface for simple, reliable, and adjustable actuation of the centrifuge. The centrifuge is designed to allow for simple disassembly, maintenance, and repair as needed, and to allow for modifying the flow path to adjust (increase or decrease) the residence time of the material as desired.
One embodiment of the inventive centrifuge for decanting lighter material from heavier material from a mixture of initial material includes a housing having a central body and a hollow arm extending from the body, the arm having a first end attached to the central body, and a second end extending away from the central body, and an end cap attached to the second end of the arm to form a chamber in the arm. A baffle is attached to the body and extends into the chamber, the baffle having a longer inner tube having an interior and a distal end, and a shorter outer tube. The longer tube is positioned inside the shorter tube and defines an inner space therebetween. An outer space is defined between the shorter tube and the hollow arm. An entrance path for the mixture of initial material is formed in the housing and communicates with the inner space. An exit path for the light material is formed in the housing and communicates with the outer space. An exit path for the heavier material is formed in the housing and includes the interior of the longer tube. During operation the heavy material migrates outwardly and the lighter material migrates inwardly. A plug of the heavy material is formed in the chamber adjacent the end cap to engage the distal end of the longer tube and define a flow path to guide the lighter material to the light material exit path.
The baffle can have a plurality of longer and shorter concentrically-spaced tubes to define a serpentine flow path therebetween. The baffle can also be replaced to modify the flow-path through the centrifuge as desired. The exit path for the heavier material can include flighted conveyor screws to assist in moving the heavier material along the exit path to the heavy material outlet port. The conveyor screws can be actuated by the rotation of the centrifuge, and thus do not independently require an external drive means.
In another embodiment, a rotating centrifuge For decanting lighter material from heavier material from a mixture of initial material includes a housing having a central body, a baffle engaging the body, the baffle having a longer inner tube having an interior and a distal end, and a shorter outer tube, the longer tube positioned inside the shorter tube and defining an inner space therebetween. A hollow arm extends from the central body, the arm having a first end engaging the baffle, and a second end extending away from the central body. An end cap engages the second end of the arm to form a chamber in the arm, the end cap attached to the central body by a through-bolt extending from the end cap to the central body, and clamping the baffle and the hollow arm between the end cap and the central body. An outer space is defined between the shorter tube and the hollow arm, and an entrance path for the mixture of initial material is formed in the housing and communicates with the inner space. An exit path for the light material is formed in the housing and communicates with the outer space, and an exit path for the heavier material is formed in the housing and includes the interior of the longer tube.
Accordingly, it is an object of the present invention to provide a centrifuge that allows the flow path and separation force to be easily modified.
Other aspects, features and details of the present invention can be more completely understood by reference to the following detailed description of a preferred embodiment, in conjunction with the drawings, and from the appended claims.